106 votes
Accepted

Why is Python used on aircraft although it may not be certifiable?

Just because aviation developers use Python, does not mean that Python actually goes flying. Lots of aviation development is about testing, stressing, validating, analyzing, and documenting the code ...
abelenky's user avatar
  • 30.7k
104 votes
Accepted

If a pilot ejects, what is the autopilot programmed to do?

I would want to build in a way for the plane to try and save itself if possible (to save money) by auto-landing Had the situation allowed saving the airplane the human pilot would definitely have ...
Hanky Panky's user avatar
  • 6,011
71 votes
Accepted

How dissimilar are redundant flight control computers?

As far as Airbus is concerned: Each unit is composed of two dissimilar boards, one driving the output and the other checking it. Dissimilar means both different CPUs and chipsets (A320 uses i386 (...
Jan Hudec's user avatar
  • 56.2k
62 votes

If a pilot ejects, what is the autopilot programmed to do?

To add some context to the other answers... Ejection is not a safe thing to do. The two most popular ejection systems today, the ACES II and Martin-Baker, have around a 90-92% success rate... the ...
tj1000's user avatar
  • 8,757
48 votes

If a pilot ejects, what is the autopilot programmed to do?

Whatever it was programmed to do at the moment the pilot ejected. Ejection seats are complex enough without integrating special processing of the event into the autopilot. Since the autopilot can't ...
Therac's user avatar
  • 25.5k
40 votes

How dissimilar are redundant flight control computers?

Redundancy is not only achieved by multiplying the computers, but also by diversifying them. On Airbus airliners, two different computers are used (one with Intel chips, the other with Motorola chips ...
Peter Kämpf's user avatar
35 votes

Why is Python used on aircraft although it may not be certifiable?

As a software engineer who works at a defence company that develops and sells mission critical (but not safety critical) systems, I can confirm that there's a pretty even split between development in ...
T. Archer's user avatar
  • 451
28 votes
Accepted

Is there an audible warning on commercial aircraft if you try to land gear up?

All turbine-powered aircraft used in scheduled airline service under CFR Part 121 are required to have an approved TAWS installed; §121.354 Terrain awareness and warning system. (a) ...
Gerry's user avatar
  • 19.7k
18 votes

Can a IFR flight plan be amended or cancelled whilst in flight?

Yes, an IFR flightplan can be cancelled at any time. The pilot simply tells ATC "cancelling my IFR flight", then it is cancelled. Depending on airspace classification, ATC may need to issue ...
60levelchange's user avatar
14 votes

Why is Python used on aircraft although it may not be certifiable?

There are three basic areas of coding for aviation engineers. Software code that runs on flight computers and other avionics equipment, software that formally verifies and creates that code, and ...
Cody P's user avatar
  • 6,775
12 votes

How dissimilar are redundant flight control computers?

In general, software isn't manufactured wrong. When the software is created (programmed), defects can be introduced as you described by either faulty implementations or by bad specifications. Faulty ...
bjelleklang's user avatar
  • 3,981
12 votes

Which CPUs and programming languages are used in new airliner flight control systems?

Note: I focused more on changes in aviation hardware and software than what's currently used since the question linked about programming languages is still current for "new" aircraft. I do not wish ...
Cody P's user avatar
  • 6,775
12 votes

How did the Thrust Reverser Deploy in Lauda Air Flight 004 crash?

The investigation into Lauda Air Flight 004 determined that the probable cause was the deployment of the left engine thrust reverser (TR) during climb. An unsuspecting crew would not be able to ...
fooot's user avatar
  • 72.8k
12 votes

United’s 787-9 upgrade

This is not at all uncommon in car engines, and optimization can be done in jet engines also. For longevity and safety reasons engines are not ran to their full capacity (except in drag race cars), ...
Jpe61's user avatar
  • 28k
11 votes

How does Jeppesen create its US charts?

FAA/NACO charts aren't masters, either The master form of a FAA instrument approach procedure isn't the FAA/NACO approach plate for that procedure -- that plate is a derived document, just like the ...
UnrecognizedFallingObject's user avatar
10 votes

How much computing power is needed to keep commercial and military planes flying?

For commercial airliners: the computing power is set during development and certification of the type. The A320 was developed in the 1980s and still uses Intel 80186 and Motorola 68020 processors. ...
Koyovis's user avatar
  • 61.6k
10 votes

Why does my flightplan generator come up with a very non-direct route between these two airports?

I assume you used some kind of "use airways" option to vector you on an airway flight and generate this path. First and foremost a quick note, this path, for a small single engine trainer is outright ...
Dave's user avatar
  • 101k
10 votes
Accepted

Are there certification requirements for software that is intended to be used in flight, but runs on uncertified hardware and is not safety-critical?

Tablets and other portable devices are not part of the aircraft's type certificate, so they are not required to be certified. Therefore, neither is the software. For equipment permanently installed ...
Michael Hall's user avatar
  • 25.7k
8 votes
Accepted

How does a PFD handle unphysically abrupt changes in the parameters it's displaying?

Generally, PFD will smoothen the indication for most of the indicated data. I don't know any 'legal' requirements for it, but as you mention, basic ergonomics require it. I have first hand ...
Zeus's user avatar
  • 9,053
8 votes
Accepted

What are these symbols in Garmin Pilot?

Those are the highest obstacle and highest terrain point along the route, respectively. They're both grey because they're well below your planned altitude, so they're no factor. You can see them by ...
Pondlife's user avatar
  • 71.7k
8 votes
Accepted

What CAD software is most commonly used for aircraft design?

It really depends upon what you’re designing or analyzing, and what company you work for. In regards for structural design, at the major OEMs, CATIA V5 and V6 are the most common. This is ...
Romeo_4808N's user avatar
  • 73.5k
7 votes

Is there an audible warning on commercial aircraft if you try to land gear up?

More basic than the TAWS requirement are the certification requirements for transport category aircraft, specifically 14 CFR 25.729(e)(2) 14 CFR 25.729 (e) Position indicator and warning device. If ...
Sports Racer's user avatar
  • 2,648
7 votes

How is device control software checked for quality?

I've worked on some certified software in a different domain (and slightly less strict); the principle would be similar here. Basically the certifying authority will want to make sure that proper ...
Jan Hudec's user avatar
  • 56.2k
7 votes
Accepted

United’s 787-9 upgrade

Complex Control There are a non-trivial number of actuators in a modern jet engine. In addition to the throttle, there are valves which control bleed air at different stages of the engine, stator ...
Lawnmower Man's user avatar
6 votes

How to decode ARINC 429 data?

ARINC 429 is a defined standard that not only describes the packet structure (32 bits) but also the data formats for different labels depending on the equipment ID. To know how to properly decode an ...
selectstriker2's user avatar
6 votes

Is it legal to use an online logbook?

I've been using myflightbook.com for a couple of years now. It is free, easy to use, and very comprehensive. I've flown over 100 different aircraft types and am rated in several different categories ...
Alan Brown's user avatar
6 votes
Accepted

What software generated this VFR flight plan?

This flight plan was generated with Skyvector Click here for the specific flight plan from your example Then click "Nav Log" for the log itself.
Steve V.'s user avatar
  • 23.2k
6 votes

What has been done to provide security for remote wireless updating of in-aircraft software components?

Boeing claims in this document: The 787 uses wireless (802.11 b/g) technology while at the gate to transfer maintenance data and update the Electronic Flight Bag (EFB). This is referred to as “...
Peter Kämpf's user avatar
6 votes

How does Jeppesen create its US charts?

Considering that Jeppesen provides their products in several different formats, such as the paper charts, their JeppView application for iPad EFB's, and database subscriptions for aircraft Flight ...
Ralph J's user avatar
  • 50.7k
6 votes

How is device control software checked for quality?

All software running on certified equipment will have to follow RTCA DO-178C. This is a fairly complex and expensive process that includes audits specifically with the certification authority (FAA, ...
selectstriker2's user avatar

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